package com.mecuros.gateway.filter;

import com.mecuros.common.core.constant.SecurityConstants;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.Arrays;
import java.util.stream.Collectors;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR;
import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.addOriginalRequestUrl;

/**
 * @author yujianbo
 * @Classname CarlosRequestGlobalFilter
 * @Description 全局拦截器，作用所有的微服务
 * @Date 2022/4/28 9:03 下午
 */
public class CarlosRequestGlobalFilter implements GlobalFilter, Ordered {

    /**
     * Process the Web request and (optionally) delegate to the next {@code WebFilter}
     * through the given {@link GatewayFilterChain}.
     * @param exchange the current server exchange
     * @param chain provides a way to delegate to the next filter
     * @return {@code Mono<Void>} to indicate when request processing is complete
     */
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 1. 清洗请求头中from 参数
        ServerHttpRequest request = exchange.getRequest().mutate()
                .headers(httpHeaders -> httpHeaders.remove(SecurityConstants.FROM)).build();

        // 2. 重写StripPrefix
        addOriginalRequestUrl(exchange, request.getURI());
        String rawPath = request.getURI().getRawPath();
        String newPath = "/" + Arrays.stream(StringUtils.tokenizeToStringArray(rawPath, "/")).skip(1L)
                .collect(Collectors.joining("/"));

        // if (rawPath.contains("/v3/api-docs/")) {
        // newPath = "/admin/v3/api-docs";
        // }
        ServerHttpRequest newRequest = request.mutate().path(newPath).build();
        exchange.getAttributes().put(GATEWAY_REQUEST_URL_ATTR, newRequest.getURI());

        return chain.filter(exchange.mutate().request(newRequest.mutate().build()).build());
    }

    @Override
    public int getOrder() {
        return -1000;
    }

}

